The Miracle of SilkAfter 4000 years, nature and science have joined forces to produce silk long underwear which can help thermo-regulate the body's temperature and dramatically speed up the dispersion and rapid evaporation of the body's perspiration. Ideal for layering, travelwear and everyday use, the Terramar Men's Tall ThermaSilk ec2 Lightweight Silk Long Sleeve Crewneck Shirt is naturally incredibly soft, warm, breathable and extremely lightweight. A perfect solution for cold weather uses, the ThermaSilk Crewneck Shirt will ensure you stay dry, warm and comfortable in all outdoor adventure activities.Constructed of ThermaSilk 100% pure filament silk interlock.ThermaSilk is the ideal fabric for next-to the-body comfort.ec2 Qwik-Dri Thermoregulation Comfort Technology is an electrostatic process that allows for moisture movement without the garment touching the skin.Crew neck.Saddle shoulders allow a full range of motion without binding. 1x1 rib trim with spandex will not loose its shape.Anti-microbial treatment for odor control.Luxurious, soft and breathable.Warmth without bulk.Provides excellent moisture management.Designed to give thermal protection in cold to very cold weather with medium to high activity.Excellent thermal qualities in a variety of weather conditions.Avg. wt. 3.4 oz. Import.